The proposed research is concerned with the development of semantic memory. One series of experiments explores the possibility that the features attended to by young children, and therefore most strongly represented in their memories, are not those on which adults have learned to rely. These experiments use a cued recall paradigm to assess the relative importance of categorical, perceptual, functional, and locational relationships as encoding and retrieval dimensions for kindergarten, grade school, and adult subjects as a function of mode of stimuli presentation (i.e., visual or verbal). One explanation for the young child's apparent reliance on context and co-occurrence as bases for association is that he has difficulty analyzing his experiences into features according to which words and objects can be compared and contrasted. Opposites represents the simplest form of feature contrast; thus, children's understanding of opposition can be used as an index of their progress in building a semantic feature system. The second series of experiments uses a number of experimental techniques to examine the development of semantic connections between opposites as a function of the semantic and formal nature of the opposition. This research has direct implications for curriculm planning for the early school years.